1. Field of the Invention
The application relates to a process for making lubricant additives. In particular, it relates to a process for making a diorganicammonium phosphorothioate.
2. Discussion of the Prior Art
The organicammonium diaryl phosphorothioates are well known materials, useful as ashless antiwear additives in lubricants and other industrial oils. There are methods known to those skilled in the chemical arts for making the compounds, but they are generally complex and give low yields of product. One prior art method involves the following scheme, using, for example, phenol, thiophosphoryl chloride and butylamine: ##STR1##
In contrast, my process is straightforward and provides products of excellent quality in nearly quantitative yields. It has, among others, the advantage that I can prepare the diaryl phosphonate in excellent yields by the conventional process in which phenol is reacted with phosphorus trichloride.